Prognostic relevance of surface markers in adult de novo acute myeloblastic leukemias: a prospective study of the Groupe d'Etude Immunologique des Leucémies (G.E.I.L.)

Outcome of adult patients with acute myeloid leukemia who failed to achieve complete remission after one course of induction chemotherapy: a report from the BGMT Study Group

Between 50 and 75% of adult patients with de novo acute myeloid leukemia achieve complete remission (CR) but 25 to 40% of them require more than one course of induction chemotherapy to achieve CR. In order to investigate the impact of this situation on the overall outcome of patients we conducted a retrospective analysis of 130 patients, resistant to a single induction course from among three consecutive protocols, using the same induction regimen employed by the BGMT study group. This group of patients has a particularly poor prognosis with relapse and survival rates of 70% and 14% respectively at 5 years. For these patients, being in CR after two induction courses appears to be a major prognostic factor for outcome, since the 5-year Kaplan-Meier survival probability is significantly better (29%, range 17-46) than of those patients with resistant disease (5%, range 2-13). However, results are worse than when complete remission is obtained after a single course. Thus, post remission treatment should have a powerful anti-leukemic effect in preventing relapse. Allogeneic bone marrow transplantation is a preferential strategy in this setting but to be effective this should be performed as early as possible. Furthermore, these results indicate that allogeneic bone marrow transplantation from an alternative donor should be considered in the absence of HLA identical sibling.

PreB1 (CD10-) acute lymphoblastic leukemia: immunophenotypic and genomic characteristics, clinical features and outcome in 38 adults and 26 children. The Groupe dEtude Immunologique des Leucémies

The less differentiated stage (CD10-) of B-lineage acute lymphoblastic leukaemia (ALL) described as preB1-ALL in the GEIL nomenclature, accounts for less than 10% of ALL. It is classically considered to be associated with translocation (4;11)(q21;q23), and to have a poor prognosis. We report an extensive immunophenotypic, genomic and clinical study of a series of 64 preB-1 ALL patients, representing 6.3% of a cohort of consecutive ALLs. The engagement of preB1-ALL cells in the B-lineage was confirmed by their B-lineage score, equal to or higher than 2. In addition, more than 90% of the cases tested showed rearranged IGH genes. Translocation (4;11) was the most frequent karyotypic anomaly seen, but only accounted for 24% of the preB1-ALL cases tested. Expression of the myeloid associated antigen CD15 was also found with high incidence in this subset. Clinical and biological features at presentation showed more significant differences between preB1- and T-ALL than between preB1- and preB2-ALL (CD10+). However, outcome characteristics of the 22 children with preB1-ALL confirmed the worse prognosis of this entity.